Strongly disagree. I think most ordinary people expect roughly every email address to end with .com. I think some people might be ok with eg .co.<country-code> (in that country) or .org, but I would expect you to risk them writing down .com anyway. If you give an address like abc.xyz, you risk people not believing that it’s a real address and doing weird things or random problems with spam filters not liking the tld.

True. People have emailed me at myemail.mydomain@gmail.com instead of myemail@mydomain.com even when given in writing. I found it that they cc'ed the correct one just in case.

I would guess a lot of people would just (silently) add the .com when you told them me@abc.xyz resulting in me@abc.xyz.com

Hm that depends on the country though. The local TLD (.us, .fr, .hr, …) would be rather common I’d say.

Apart from that, it’s mostly what people browse to, yes. So .com, .net, .org.

Country code domains are common in many countries outside the USA.

If it's clear I'm not local, something like "yahoo.ca" or "mail.ru" is not confusing, except perhaps for Colombians (.co). A local with an address in the "wrong" country can be confusing if it's obscure.

Within a country, using a less-common second level domain (e.g. .org.uk) for a personal domain can be confusing. I've had people say "so that's example.org.uk.com then?" or "what was that, symbiote-example.org.uk@gmail?"

You'd be amazed at how many people get confused about "new" TLDs (not .com, .net, .org, .edu, or .gov). I have an email account that's @mylastname.io, and I had to buy mylastnameio.com because I got tired of not getting emails because the "silent failure" where a rep thought they entered my email right but totally didn't.

I diagree. The c / z in American pronunciation can cause confusion in verbal communication here. "at ey bee [see] dot ex why [see]"